CN101136921B - Communication apparatus and communication system - Google Patents

Abstract

The invention provides a transmission apparatus and transmission system to achieve a link aggregation function and maintenance function by MPLS OAM. Identical entry information is stored in plural circuits IF11, IF12 which perform a LAG setting. In this way, multiplexing to the same LSP is possible even with different IF. The circuit IF11 is assumed to be OAM ACT, and the circuit IF12 is set to OAM SBY. OAM frame insertion is performed only by an OAM ACT port. In this way, in an opposite MPLS transmission apparatus, it is possible to prevent CV frame reception above a specified number of frames. Further, a switch forwarding table is set to forward frames from the network side to the circuit IF11 of OAM ACT. The circuit IF12 which was set to OAM SBY does not perform fault detection by CV reception. In this way, incorrect detection of faults due to non-reception of OAM can be prevented.

Description

Communication device and communication system

technical field

The present invention relates to a communication device and a communication system, in particular to a communication device and a communication system with link set and MPLS OAM functions. the

Background technique

Means that provide a function known as Link Aggregation (LAG) are known. LAG is a technology that combines multiple physical ports as one logical port between two devices. The device corresponding to the LAG selects the output physical port belonging to the LAG port based on the identification information (ID) for specifying the flow (flow) such as VLAN (Virtual LAN) tag and MAC. the

In addition, the MPLS (Multi-Protocol Label Switching) communication device includes, for example, a device that determines an MPLS LSP (Label Switching Path) connection based on a VLAN. The MPLS communication device with the maintenance function based on MPLS OAM (Operations Administration and Maintenance) monitors the end-to-end (EtoE) connectivity of the connection by periodically transmitting the Continuity Confirmation (CV) frame. When each interface does not receive a CV frame, it is determined that a failure has occurred, and the connection is switched from system 0 to system 1. the

Non-Patent Document 1 ITU-T Protocol Y.1710S ERIES Y: GLOBAL INFORMATION INFRASTRUCTURE AND INTERNET PROTOCOL ASPECTS, Internet protocols-Operation, administration and maintenance

Non-Patent Document 2 ITU-T Protocol Y.1720 SERIES Y: GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS Internet protocol aspects-Operation, administration and maintenance Protection switching for MPLS networks

非专利文献3 IEEE Standard for Information technologyTelecommunications and information exchange between systems Localand metropolitan area networks Specific requirementsPart3：Carrier sense multiple access with collision detection(CSMA/CD)access method and physical layerspecifications Sections3 Chapter43 pp.285-350 

In a device connecting an Ethernet (registered trademark, the same hereinafter) network and an MPLS network, the two networks may take path (pass) redundancy. The layers of the Ethernet and the MPLS network are different, but the carrier (carrier) attaches importance to reliability and uses the MPLS network, while the user side uses the relatively cheap Ethernet. The redundant structures of Ethernet and MPLS networks are realized by using different functions, so it was difficult to provide coherent redundant paths in the past. the

Also, there is no known system for connecting a device corresponding to LAG and an MPLS communication device having an MPLS OAM function. When connecting them, there are, for example, the following problems. the

A LAG combines multiple physical ports as one logical port. The VLAN flow input from the LAG port to the MPLS communication device needs to be transmitted through the same MPLS LSP connection even if the physical port (line interface) is different. However, in conventional MPLS communication devices, streams input to different IFs cannot be transmitted through the same MPLS LSP connection. the

And, when there are two OAM insertion points of the device A, at the opposite OAM end point of the device B, two CV frames arrive from the same MPLS connection within a predetermined time. In a normal OAM endpoint, the normality of the connection is confirmed by the arrival of a CV frame within a predetermined time, so that in the above state it will lead to misidentification. the

In addition, since the switch unit of device A assigns the frame transfer location according to the LSP ID (label), the traffic from device B to device A is biased toward one of the physical ports corresponding to the LAG port. Therefore, in a physical port that cannot receive traffic, CV frames cannot be received. Physical ports that cannot receive CV frames sometimes falsely detect failures. the

Contents of the invention

The present invention is proposed in view of the above circumstances, and its purpose is to provide a communication device and a communication system that can provide redundancy of Ethernet sections based on link sets and redundancy of MPLS sections based on maintenance functions using MPLS OAM change. Furthermore, an object of the present invention is to transfer frames received on a plurality of interfaces corresponding to a link set to the same path. The purpose of the present invention is to prevent false detection of MPLS OAM faults. In addition, another object of the present invention is to prevent user frames from being biased towards one of a plurality of interfaces corresponding to a link set. the

The same entry information is stored in, for example, a labeling table among a plurality of physical ports set in the LAG. This enables multiplexing to the same LSP between different IFs. the

One of the multiple physical ports is defined as OAM ACT (action), and the other ports are defined as OAM SBY (preparation). OAM frames are sent only to OAM ACT ports. This prevents the opposing MPLS communication device from receiving more than a predetermined number of CV frames. the

Only ports defined as OAM ACT receive OAM frames. Other ports are defined as OAM SBY, and no fault detection based on CV reception is performed. For example, regarding the setting of the transfer table of the switch, for frames received from the MPLS network side, the transfer point is set as the physical port set for OAM ACT, so that the OAM frame can be terminated by the OAM ACT port. In this way, erroneous detection of failures based on non-received OAM can be prevented. the

And, when the OAM ACT port is blocked due to an Ethernet link failure, switch the OAM SBY to ACT. Also, change the transfer location based on the switch to the switched OAM ACT port. When there are multiple OAM SBY ports, priority can also be given. the

According to the first solution of the present invention, a communication device is provided, which binds a plurality of physical ports to be used as one logical port. Any physical port that transmits the frame is connected to the first communication device, and is connected to the second communication device through a communication network that adopts a redundant structure via the first path and the second path, and the frame input from the first communication device is transmitted in accordance with The label is packaged and sent to the second communication device, the label is removed from the frame input by the second communication device and unpacked, and sent to the first communication device, with:

The first interface part for connecting to the first path;

The second interface part for connecting to the second path;

A third interface portion for connecting to a first physical port of the first communication device constituting a link aggregation port;

A fourth interface section for connecting to a second physical port of the first communication device constituting a link aggregation port; and

The exchange unit has a transfer table that stores the identifiers of the first to fourth interface units as output location information in tags corresponding to the first route and the second route, and refers to the Transmission table, transmit frames according to the corresponding output location information,

The third interface unit has a first storage unit for setting the operation system or the preparation system for fault detection, and the first storage unit is set as the operation system,

The fourth interface unit has a second storage unit for setting an operation system or a standby system for fault detection, and the second storage unit is set as a standby system,

The third interface unit receives the user frame sent from the first physical port of the first communication device, packs the user frame according to the label of the first path, and transmits the user frame through the first path via the switching unit For the 2nd communication device,

The fourth interface unit receives the user frame sent from the second physical port of the first communication device, packs the user frame according to the label of the first path, and transmits the user frame through the first path through the switching unit For the 2nd communication device,

The third interface unit transmits a conduction confirmation frame to the second communication device based on the first storage unit set as the operating system,

The fourth interface unit does not transmit a conduction confirmation frame to the second communication device based on the second storage unit set as a standby system,

The transfer table stores at least an identifier of the third interface unit set as an operating system as a link to the downlink received by the first and second interface units through the first and second paths. The output location information corresponding to the tag, the switching unit transmits the conduction confirmation frame received from the second communication device through the first path and the second path to the third interface unit according to the transmission table,

The third interface unit receives a conduction confirmation frame transmitted at predetermined intervals by the second communication device, and passes the conduction confirmation frame not received based on the first storage unit set as an operation system. to detect the failure of the 1st or 2nd path,

The fourth interface unit does not perform failure detection due to failure to receive a continuity confirmation frame based on the second storage unit set as a standby system,

The communication device further includes a control unit that controls the third interface unit, the fourth interface unit, and the switching unit,

When the third interface unit detects a link failure with the first communication device, the first storage unit is set as a backup system, and a switching notification is sent to the control unit,

When the control unit receives the switching notification, it sets the second storage unit of the fourth interface unit as an operating system,

The control unit changes the output destination information corresponding to the labels in the downstream direction of the first bus and the second bus in the transfer table to an identifier set as the fourth interface unit of the operating system, thereby The conduction confirmation frame received from the second communication device through the first bus and the second bus is transmitted to the fourth interface unit according to the transmission table. the

According to the second solution of the present invention, a kind of communication device is provided, and a plurality of physical ports are bundled and used as one logical port, and when the output location of the received frame is the logical port, that is, the link set port, it is connected to the link set port. Any physical port that transmits the frame is connected to the first communication device, and is connected to the second communication device through a communication network that adopts a redundant structure via the first path and the second path, and the frame input from the first communication device is transmitted in accordance with The label is packaged and sent to the second communication device, the label is removed from the frame input by the second communication device and unpacked, and sent to the first communication device, with:

The first interface part for connecting to the first path;

The second interface part for connecting to the second path;

A third interface portion for connecting to a first physical port of the first communication device constituting a link aggregation port;

A fourth interface section for connecting to a second physical port of the first communication device constituting a link aggregation port; and

The exchange unit has a transfer table that stores the identifiers of the first to fourth interface units as output location information in tags corresponding to the first route and the second route, and refers to the Transmission table, transmit frames according to the corresponding output location information,

The third interface unit has a first storage unit for setting the operation system or the preparation system for fault detection, and the first storage unit is set as the operation system,

The fourth interface unit has a second storage unit for setting an operation system or a standby system for fault detection, and the second storage unit is set as a standby system,

The third interface unit receives the user frame sent from the first physical port of the first communication device, packs the user frame according to the label of the first path, and transmits the user frame through the first path via the switching unit For the 2nd communication device,

The fourth interface unit receives the user frame sent from the second physical port of the first communication device, packs the user frame according to the label of the first path, and transmits the user frame through the first path through the switching unit For the 2nd communication device,

The third interface unit transmits a conduction confirmation frame to the second communication device based on the first storage unit set as the operating system,

The fourth interface unit does not transmit a conduction confirmation frame to the second communication device based on the second storage unit set as a standby system,

The transfer table corresponds to the downlink labels received by the first and second interface units through the first and second paths, and stores at least an identifier indicating a link set as the first output location information for the user frame. , and as the second output location information for the conduction confirmation frame is set as the identifier of the third interface part of the operating system,

The switching unit identifies whether the frame received from the second communication device is a user frame or a continuity confirmation frame,

If it is a user frame, according to a preset rule, select one of the interface units belonging to the link set indicated by the first output location information in the transfer table, and communicate with the first communication unit through the selected interface unit The device transmits the frame,

If it is a conduction confirmation frame, then transmit the frame to the third interface part according to the second output location information of the transmission table,

The third interface unit receives a conduction confirmation frame transmitted at predetermined intervals by the second communication device, and passes the conduction confirmation frame not received based on the first storage unit set as an operation system. to detect the failure of the 1st or 2nd path,

The fourth interface unit does not perform failure detection due to non-reception of a continuity confirmation frame based on the second storage unit set as a standby system. the

According to the third scheme of the present invention, a kind of communication system is provided, has:

The first communication device binds a plurality of physical ports as one logical port, and when the output location of the received frame is the logical port, that is, the link set port, transmits the frame to any physical port in the link set port;

The second communication device is connected via a redundant communication network via the first path and the second path; and

The third communication device is connected with the first communication device and the second communication device, packs the frame input from the first communication device according to the label and transmits it to the second communication device, and the frame is received by the second communication device. 2 remove the label from the frame input by the communication device and unpack it, and send it to the first communication device,

The third communication device has:

The first interface part for connecting to the first path;

The second interface part for connecting to the second path;

A third interface portion for connecting to a first physical port of the first communication device constituting a link aggregation port;

A fourth interface section for connecting to a second physical port of the first communication device constituting a link aggregation port; and

The exchange unit has a transfer table that stores the identifiers of the first to fourth interface units as output location information in tags corresponding to the first route and the second route, and refers to the Transmission table, transmit frames according to the corresponding output location information,

The third interface unit has a first storage unit for setting the operation system or the preparation system for fault detection, and the first storage unit is set as the operation system,

The fourth interface unit has a second storage unit for setting an operation system or a standby system for fault detection, and the second storage unit is set as a standby system,

The third interface unit receives the user frame sent from the first physical port of the first communication device, packs the user frame according to the label of the first path, and transmits the user frame through the first path via the switching unit For the 2nd communication device,

The fourth interface unit receives the user frame sent from the second physical port of the first communication device, packs the user frame according to the label of the first path, and transmits the user frame through the first path through the switching unit For the 2nd communication device,

The third interface unit transmits a conduction confirmation frame to the second communication device based on the first storage unit set as the operating system,

The fourth interface unit does not transmit a conduction confirmation frame to the second communication device based on the second storage unit set as a standby system,

The transfer table stores at least an identifier of the third interface unit set as an operating system as a link to the downlink received by the first and second interface units through the first and second paths. The output location information corresponding to the tag, the switching unit transmits the conduction confirmation frame received from the second communication device through the first path and the second path to the third interface unit according to the transmission table,

The third interface unit receives a conduction confirmation frame transmitted at predetermined intervals by the second communication device, and passes the conduction confirmation frame not received based on the first storage unit set as an operation system. to detect the failure of the 1st or 2nd path,

The fourth interface unit does not perform failure detection due to non-reception of a continuity confirmation frame based on the second storage unit set as a standby system. the

According to the fourth scheme of the present invention, a kind of communication system is provided, has:

The first communication device binds a plurality of physical ports as one logical port, and when the output location of the received frame is the logical port, that is, the link set port, transmits the frame to any physical port in the link set port;

The second communication device is connected via a redundant communication network via the first path and the second path; and

The third communication device is connected with the first communication device and the second communication device, packs the frame input from the first communication device according to the label and transmits it to the second communication device, and the frame is received by the second communication device. 2 remove the label from the frame input by the communication device and unpack it, and send it to the first communication device,

The third communication device has:

The first interface part for connecting to the first path;

The second interface part for connecting to the second path;

A third interface portion for connecting to a first physical port of the first communication device constituting a link aggregation port;

A fourth interface section for connecting to a second physical port of the first communication device constituting a link aggregation port; and

The exchange unit has a transfer table that stores the identifiers of the first to fourth interface units as output location information in tags corresponding to the first route and the second route, and refers to the Transmission table, transmit frames according to the corresponding output location information,

The third interface unit has a first storage unit for setting the operation system or the preparation system for fault detection, and the first storage unit is set as the operation system,

The fourth interface unit has a second storage unit for setting an operation system or a standby system for fault detection, and the second storage unit is set as a standby system,

The third interface unit receives the user frame sent from the first physical port of the first communication device, packs the user frame according to the label of the first path, and transmits the user frame through the first path via the switching unit For the 2nd communication device,

The fourth interface unit receives the user frame sent from the second physical port of the first communication device, packs the user frame according to the label of the first path, and passes the user frame through the first path through the switching unit sent to the second communication device,

The third interface unit transmits a conduction confirmation frame to the second communication device based on the first storage unit set as the operating system,

The fourth interface unit does not transmit a conduction confirmation frame to the second communication device based on the second storage unit set as a standby system,

The transfer table corresponds to the downlink labels received by the first and second interface units through the first and second paths, and stores at least an identifier indicating a link set as the first output location information for the user frame. , and as the second output location information for the conduction confirmation frame is set as the identifier of the third interface part of the operating system,

The switching unit identifies whether the frame received from the second communication device is a user frame or a continuity confirmation frame,

If it is a user frame, according to a preset rule, select one of the interface units belonging to the link set indicated by the first output location information in the transmission table, and transmit to the first communication device through the selected interface unit frame,

If it is a conduction confirmation frame, then transmit the frame to the third interface part according to the second output location information of the transmission table,

The third interface unit receives a conduction confirmation frame transmitted at predetermined intervals by the second communication device, and passes the conduction confirmation frame not received based on the first storage unit set as an operation system. to detect the failure of the 1st or 2nd path,

The fourth interface unit does not perform failure detection due to non-reception of a continuity confirmation frame based on the second storage unit set as a standby system. the

According to the present invention, there are provided a communication device and a communication system capable of realizing redundancy of Ethernet sections based on link sets and redundancy of MPLS sections based on a maintenance function using MPLS OAM. Also, according to the present invention, frames received on a plurality of interfaces corresponding to a connection set can be transferred to the same LSP. According to the present invention, false detection of MPLS OAM faults can be prevented. Also, according to the present invention, it is possible to prevent user frames from being biased towards one of a plurality of interfaces corresponding to a link set. the

Description of drawings

Fig. 1 is the schematic diagram of LAG;

Fig. 2 is a schematic diagram of an MPLS network and an MPLS communication device connected with an MPLS communication device supporting MPLS OAM;

Fig. 3 is the schematic diagram of MPLS network frame and transmission table 310;

Fig. 4 is the structural diagram (1) of the circuit IF of MPLS communication device;

Figure 5 represents the frame format within the line IF;

Fig. 6 is the figure (1) that represents the structure example of each table;

Fig. 7 is the figure (2) that represents the structure example of each table;

Figure 8 represents the MPLS OAM format;

Fig. 9 is a schematic diagram (1) of switching between the operating system/standby system when the 0 system (operating system) fails;

Figure 10 is a schematic diagram (2) of switching between the operating system/standby system when the 0 system (operating system) fails;

Figure 11 is a diagram showing a system switching program based on unreceived CV;

Fig. 12 is the flow chart that represents the IF control CPU110 of CV not receiving detection node;

Fig. 13 is the flow chart that represents the IF control CPU110 of APS request receiving node;

Fig. 14 is the schematic diagram representing the problem of the communication device with LAG and MPLS OAM function;

Fig. 15 is a structural diagram of the system of the first embodiment;

Fig. 16 is the structural example of transmitting table 310 and LAG information database;

Fig. 17 is the structural diagram of circuit IF10;

Figure 18 is a schematic diagram of the switching action of ACT/SBY when a fault occurs in the Ethernet section;

Fig. 19 is the example of the table structure after switching when the Ethernet interval produces a fault;

Fig. 20 is a switching flowchart (1) when a fault occurs in the Ethernet interval;

Fig. 21 is a switching flowchart (2) when a fault occurs in the Ethernet section;

Figure 22 is a schematic diagram of active/standby switching when a fault occurs in the MPLS section;

Figure 23 is a flow chart of the active/prepared handover when a fault occurs in the MPLS section;

Fig. 24 is a structural diagram of the system of the second embodiment;

FIG. 25 is a configuration diagram of a transfer table 320 according to the second embodiment. the

Explanation of reference signs

1, 2 MPLS communication device; 10, 11, 12 line IF; 21, 22 uplink IF; 30 switch; 40 overall control CPU; 50 LAG information database; 310 has transmission table; 101 frame receiving circuit; 102 label ID retrieval Unit; 103 Manager; 103 Label Giving Unit; 104 Switching and Sending Circuit; 105 Switching and Receiving Circuit; 106 MPLS Label Processing Unit; 107 Frame Sending Circuit; ;200 OAM ACT/SBY switching registers; 330 Hash blocks

Detailed ways

1. The first embodiment

(link collection)

Figure 1 is a schematic diagram of a LAG. First, LAG will be described. the

In a normal L2 switch (NW device) corresponding to a tagged VLAN, a relationship between a VLAN tag and an output port is set in a forwarding table. In addition, the L2 switch learns the sender's MAC address, VLAN ID, and input physical port of the input frame, and when receiving a frame with the learned MAC address and VLAN ID among the recipients, the output port is selected from the learning table. Retrieve, and exchange frames. the

One of the functions of the L2 switch is a function called Link Aggregation (LAG) that bundles a plurality of physical ports as one logical port. Here, the logical ports bundled through the LAG are called LAG ports. The LAG can provide, for example, the effect of logically increasing the line frequency band and the effect of improving redundancy. In addition, in this embodiment, for example, attention is paid to improving redundancy. A LAG port is a logical port composed of multiple physical ports (for example, physical ports 1 to 3 in FIG. 1( a )), but is recognized as one port from the perspective of the switch. the

When the LAG is set, the forwarding table of the switch sets, for example, a VLAN tag and its output port attribute. When the recipient of the received frame is sent to the LAG port, the switch transmits the frame to any physical port of the LAG port. If it is a physical port that is undergoing LAG, there is no problem to which port the frame is output according to the provisions of the LAG. Generally, when a frame is sent at a LAG port, a switch uses a hash to determine an output port. At this time, the hashing unit, for example, performs hashing calculation using the recipient's MAC address and VLAN ID, and specifies the physical port of the frame transmission location. The hash calculation result is unique, and frames with the same VLAN ID and recipient MAC are transmitted to the same physical port. Frames can be efficiently distributed among LAG ports by using shuffling. the

(MPLS)

Next, MPLS will be described based on the configuration of this embodiment. the

2 is a schematic diagram of an MPLS network and an MPLS communication device connected with an MPLS communication device supporting MPLS OAM. Fig. 3 is a schematic diagram of an MPLS network frame and a transfer table. the

MPLS is a communication protocol, which is characterized in that the input L2 frame or L3 frame is packaged and transmitted according to the MPLS label. For example, as shown in FIG. 3 , an MPLS label and a new L2 header are assigned to an input original L2 frame and transmitted. Here, MPLS for packetizing L2 frames will be described, but this function also operates in the same way for MPLS for packetizing L3 frames. In addition, in MPLS that packs L2 frames, generally many frames are packed with two MPLS labels. Here, for simplicity of description, the case where the number of labels to be assigned is one will be described. In addition, the operation of this function is the same in the method of packaging by multiple tags. The MPLS communication device uses the LSP ID in the MPLS label to determine the transmission location of the frame. the

MPLS communication device 1 includes, for example, line IF #1 (third interface unit) 11, line IF #2 (fourth interface unit) 12, uplink IF #1 (third interface unit) 21, uplink IF #2 (second interface unit) 22 , switch (SW) 30 , and overall control CPU (control unit) 40 . The overall control CPU 40 is connected to each part via a bus or the like, for example. Also, a memory may be provided as appropriate. The switch 30 has a transfer table 310 . The transmission table 310 is shown in Figure 3 (b) for example, and the output port information is stored corresponding to the LSP ID. The details of each part will be described later. the

Fig. 4 is a configuration diagram (1) of a line IF of the MPLS communication device. Each line IF11, 12 may have the same structure. the

The line IF10 has a frame receiving circuit 101, a label ID retrieval unit 102, a manager 112, a label giving unit 103, a switching transmitting circuit 104, a switching receiving circuit 105, an MPLS label processing unit 106, a frame transmitting circuit 107, an OAM terminal unit 108, an OAM Insertion unit 109 , IF control CPU 110 , and CPU interface 111 . Furthermore, the line IF10 has an entry (Ingress) label search ID table (first label search table) 150, an operating system table 160, an MPLS label table 170, an egress (Egress) label search ID table (second label search table) 180, and MPLS Label Table 190. the

6 and 7 are diagrams showing configuration examples of respective tables. the

The ingress label search ID table 150 is a table that stores label search IDs for searching the operating system table 160 and the MPLS label table 170 in correspondence with VLAN IDs. The key to this table is the VLAN ID of the received frame. The acquired tag search ID is stored by title in the device. the

The operating system table 160 is a table storing operating system information indicating a system in operation in association with a tag search ID. For example, identification information indicating a system 0 or a system 1 is stored in the system in operation. The search term in this table is the tag search ID. the

The MPLS label table 170 is a table that stores MPLS label IDs (LSP IDs, labels) assigned at the time of packaging frames in association with operating system information and label search IDs. The search terms for this table are search IDs using system information and tags. the

The egress label search ID table 180 is a table for storing the label search ID for searching the MPLS label table 190 and operating system information in association with the MPLS label ID. The key to this table is the MPLS label ID. In MPLS, different label IDs are used in upstream and downstream. Here, the tag search ID for searching an uplink tag is the same as the tag search ID acquired from a downlink tag. the

The MPLS label table 190 is a table that stores continuity confirmation information in association with operating system information and label search IDs. The search terms for this table are search IDs using system information and tags. The conduction confirmation information in this table is written with an initial value of "3", for example, when receiving a CV frame at the OAM termination unit 108, and is decremented with "1" once every second, for example, at the OAM insertion unit 109. When this value is "0", the CV has not been reached for 3 seconds or more. When this value reaches a threshold value (for example, 0), that is, when a CV does not arrive for more than 3 seconds, connection failure detection is performed. In addition, the initial value, the number to be subtracted, and the threshold for fault detection may be appropriate values. Furthermore, connection failure detection may be performed when adding up from the initial value reaches a predetermined value. the

Valid indicates validity/invalidity of the item. For example, when Valid is 1, the item is valid, and when it is 0, the item is invalid. the

Fig. 5 shows the frame format in the line IF. The intra-device frame gives the original L2 frame an intra-device header. The in-device title includes, for example, operating system information and tag search ID. the

Figure 8 shows the MPLS OAM format. the

MPLS OAM frame format for example has L2 header, MPLS label, MPLS OAM label, OAM type, OAM payload. The MPLS label includes the LSPID. An ID represented by, for example, 14 in decimal is stored in the MPLS OAM label. The OAM type stores information corresponding to CV and APS (system switching). Information indicating whether the APS is an APS request or an APS reply is stored in the OAM payload. the

Returning to Fig. 4, each unit will be described. the

The frame receiving circuit 101 receives an L2 frame from a physical port (for example, physical port #1), and assigns an in-device header to the original L2 frame (see, for example, FIG. 5 ). Here, the in-device title may be blank. The tag ID search unit 102 extracts the VLAN ID from the L2 header of the received frame, searches the entry tag search ID table 150, and acquires the corresponding tag search ID. Then, the tag ID search section 102 stores the acquired tag search ID in the device header of the received frame, and outputs the frame to the manager 112 . The manager 112 manages, for example, frame transmission. And, depending on whether the frame type is an OAM frame or a user frame, a frame identification signal is output to label assigning section 103 . the

The processing operation of label assigning section 103 differs between OAM frames and user frames. When the frame identification signal from the manager 112 is, for example, "0", it indicates a user frame. When receiving a user frame, the tag assigning unit 103 extracts the tag search ID from the header in the received frame, and acquires the operating system information corresponding to the tag search ID from the operating system table 160 . Furthermore, the label assigning unit 103 searches the MPLS label table 170 based on the acquired operating system information and the label search ID, and acquires the corresponding MPLS label ID. The label assigning unit 103 generates an MPLS label according to the MPLS label ID acquired from the table, generates an L2 header from the pre-registered new L2 header information, and packs the original L2 frame. the

On the other hand, when the frame identification signal is, for example, "1", it indicates an OAM insertion frame (CV/APS). The label assigning section 103 does not search the operating system table 160, but searches the MPLS label table 170 based on the operating system information acquired from the title in the device and the label search ID. The label assigning unit 103 packs the OAM frame according to the new L2 header and MPLS label. The switching transmission circuit 104 deletes the header in the device, and transmits the packed frame to the SW. the

The switch receiving circuit 105 receives frames from the SW. The MPLS label processing unit 106 checks the MPLS label in the frame received from the SW side, and sends the frame with the MPLS and OAM label to the OAM end unit 108 . Other frames are sent to the frame reception circuit 107 after deleting the new L2 header and MPLS label. The frame reception circuit 107 transmits a frame to a physical port (for example, physical port #1). the

The OAM inserting unit 109 searches the MPLS label table 190 for all entries once, for example, within one second. The OAM inserting unit 109 generates a payload of a CV frame for a registered item or an item whose Valid value is "1", and outputs (inserts) it to the management after adding an in-device header including the operating system information and tag search ID obtained from the table. device 112. The format of the frame inserted by the OAM insertion unit 109 is an intra-device header, MPLS OAM label, and OAM payload (including OAM type). And, the value of the conduction confirmation information of the retrieved item is subtracted by 1, for example. When the value of the conduction confirmation information is already "0", the subtraction is not performed, and the operating system information, tag search ID, and information indicating that the CV has not been received are notified to the IF control of the item whose conduction confirmation information value is "0". CPU110. the

And, the OAM inserting unit 109 inserts an APS request frame and an APS reply frame according to the instruction. the

The OAM termination unit 108 receives a frame with an MPLS OAM label from the MPLS label processing unit 106 . When the OAM end unit 108 receives the OAM frame CV, the APS request, and the APS reply, it performs different operations. CV, APS request, and APS reply can be identified, for example, based on the type value of the OAM type of the received frame, information representing the request/reply in the OAM payload, and the like. the

When receiving the CV, the OAM end unit 108 searches the egress label search ID table 180 using the MPLS label ID as a search term, and acquires the corresponding operation system information and label search ID. The OAM end unit 108 searches the MPLS label table 190 based on the operating system information and the label search ID acquired from the egress label search ID table 180, and sets the corresponding connection confirmation information to "3", for example. the

When receiving the APS request, the OAM end unit 108 uses the MPLS label ID as a search term to search the egress label search ID table 180 to obtain the corresponding operating system information and label search ID. The OAM end unit 108 notifies the IF control CPU 110 of the operation system information and the label search ID acquired from the outlet label search ID table 180 , and an APS request reception notification including information indicating reception of the APS request. the

When receiving the APS reply, the OAM end unit 108 obtains the operation system information and the label retrieval ID from the export label retrieval ID table 180 in the same way as when receiving the APS request, and stores the acquired operation system information, label retrieval ID, and The APS that has received the information of the APS reply replies to the reception notification and notifies the IF control CPU 110 . the

The IF control CPU 110 performs setting of items in each table and insertion system switching processing of APS request/reply frames. In addition, the CPU interface 111 is an interface between the IF control CPU 110 and the overall control CPU 40 . the

In the APS request insertion process, the IF control CPU 110 inputs, from the OAM insertion unit 109 , the tag search ID and operating system information of the item of conduction confirmation information “0”. The IF controls the CPU 110 to generate the payload and OAM tag of the APS request. And, an in-device title is generated. The acquired tag search ID and operating system information of the system that sent the APS request are stored in the header in the device. The operating system information of the system that sends the APS request may be one of the opposite system of the operating system notified from the OAM insertion unit 109 or a system other than the operating system. That is, the APS request is transmitted using a system different from the system in which the failure occurred. the

In the APS reply insertion process, the IF control CPU 110 inputs the above-mentioned APS request reception notification from the OAM terminal unit 108 . The notification includes retrieval IDs using system information and tags. The IF control CPU 110 generates the payload of the APS reply and the OAM tag. And, an in-device title is generated. The acquired tag search ID and operating system information are stored in the header in the device. The IF control CPU 110 adds an OAM tag and an in-device header to the payload, generates an APS reply, and outputs it to the manager 112 . APS replies are sent through the same operating system as APS requests. the

In the system switching process, the IF control CPU 110 receives the above-mentioned APS request reception notification from the OAM termination unit 108 . The notification includes tag search ID and operating system information. The IF control CPU 110 searches the operating system table 160 according to the acquired tag search ID, and rewrites the operating system information column of the table with the acquired operating system information. the

(Switching between operating system/standby system when a failure occurs - 1)

9 and 10 are schematic diagrams of switching between the operating system and the standby system when the 0 system (operating system) fails. the

For example, when a failure occurs in the downlink of system 0 (operating system), the line IF of the MPLS communication device 1 is in a state where the continuity confirmation frame is not received. Therefore, for example, the connectivity confirmation information of the MPLS label table 190 is 0 (for example, refer to FIG. 10( b )). The terminal node (for example, line IF#1 (11) of MPLS communication device 1) detects that a failure has occurred on the intermediate path due to the CV not receiving state, and transmits a system switching (APS) request frame using the uplink backup system connection (LSP1000) . The origin node (for example, line IF#1 (11) of MPLS communication device 2) that has received the APS request frame transmits an APS reply frame using the downlink backup system connection (LSP5000). The destination node that has received the APS reply frame rewrites the operating system information in the operating system table 160 so as to switch the system from system 0 to system 1 ( FIG. 10( a )). the

In this way, in the MPLS communication devices 1 and 2 that provide system switching using MPLS OAM, the non-reception of CV is used as a trigger to perform system switching. the

Fig. 11 is a diagram showing a system switching procedure based on an unreceived CV. In addition, the IF control CPU 110 in the figure is included in the line IF as described above, but for the convenience of explanation, the IF control CPU 110 and other parts are distinguished, and the parts other than the IF control CPU 110 are collectively called the line IF. the

The line IF#1 (11) of the MPLS communication device 2 transmits a CV frame to the line IF#1 (11) of the MPLS communication device 1, for example, periodically, via the path of the 0 system. Here, as an example, assume that the first CV frame arrives at the line IF #1 (11) of the MPLS communication device 1, but due to a failure in the path of the 0 system, subsequent CV frames fail to reach the line IF #1 (11) of the MPLS communication device 1. 11) to receive. the

Since the line IF#1 (11) of the MPLS communication device 2 (for example, the OAM termination unit 108) cannot receive the CV frame at the predetermined time, for example, when the conduction confirmation information of the MPLS label table 190 is 0, it notifies the MPLS communication device 1 of The IF control CPU 110 does not receive CV. The IF control CPU 110 of the MPLS communication device 1 instructs the line IF #1 (11) of the MPLS communication device 1 (for example, the OAM insertion unit 109 ) to insert an APS request. The line IF#1 (11) of the MPLS communication device 1 (for example, the OAM insertion unit 109) transmits an APS request frame to the line IF#1 (11) of the MPLS communication device 2 via 1 system. the

Line IF # 1 ( 11 ) of MPLS communication device 2 (for example, OAM termination unit 108 ) receives the APS request frame, and notifies IF control CPU 110 of MPLS communication device 2 of the received APS request. The IF control CPU 110 of the MPLS communication device 2 instructs the line IF#1 (11) of the MPLS communication device 2 (for example, the OAM insertion unit 109) to insert an APS reply. The line IF#1 (11) of the MPLS communication device 2 sends an APS reply frame to the line IF#1 (11) of the MPLS communication device 1 (for example, the OAM insertion unit 109) through 1 system according to the instruction. Then, the IF control CPU 110 of the MPLS communication device 2 rewrites the operating system information in the operating system table 160 from system 0 to system 1 . the

Line IF # 1 ( 11 ) of MPLS communication device 1 (for example, OAM termination unit 108 ) receives the APS reply frame, and notifies IF control CPU 110 of MPLS communication device 1 of the received APS reply. The IF control CPU 110 of the MPLS communication device 1 rewrites the operating system information of the operating system table 160 from system 0 to system 1 . the

FIG. 12 is a flowchart showing the IF control CPU 110 of the CV non-reception detection node. For example, a flowchart of the IF control CPU 110 of the MPLS communication device 1 in FIG. 11 . the

The IF control CPU 110 judges whether CV non-reception is detected in the operation system (S101). For example, the IF control CPU 110 refers to the operating system table 160 based on the tag search ID included in the notification from the OAM insertion unit 109 , and acquires whether the operating system is system 0 or system 1 . If the acquired operating system matches the operating system information included in the notification from the OAM insertion unit 109, it is determined that it is the operating system, and if it does not match, it is determined that it is not the operating system. When it is judged that the system is not in operation (S101, No), go to step S109. the

On the other hand, when it is judged that it is the active system, the IF control CPU 110 instructs the standby system to insert an APS request frame (S103). And, the IF control CPU 110 monitors whether or not an APS reply frame is received from the backup system (S105). For example, the reception of the APS reply frame is continuously monitored until the time is exceeded (S105, No). the

When the IF control CPU 110 receives the APS reply frame via the OAM end unit 108 (S105, YES), it changes the operating system information of the operating system table 160 corresponding to the LSP that has received the APS reply (S107). For example, rewrite the operation system information from 0 system to 1 system. For example, when an APS reply frame is received through the LSP 5000 , the OAM end unit 108 notifies the IF control CPU 110 of the tag search ID and the APS reply reception operation system that received the APS reply frame. In addition, the OAM end unit 108 may refer to the egress label search ID table 180 based on the MPLS label ID, and acquire the label search ID and operating system information. The IF control CPU 110 searches the operating system table 160 according to the tag search ID, and changes the "operating system" of the corresponding item to the system that received the APS reply frame. For example, this part may be the only place where the table is changed when the APS reply is received. More specifically, first, the operating system (for example, 1 system) and the tag search ID (for example, 1) that have received the APS are notified from the OAM end unit 108 to the IF control CPU 110 . Then, the operation system of the search ID "1" of the IF control CPU 110, that is, the operation system table 160 illustrated in FIG. 6(b) is changed from "0" to "1". the

The IF control CPU 110 notifies the overall control CPU 40 of operating system switching (S109). For example, system information after switching (for example, 1 system) is included. the

FIG. 13 is a flowchart showing the IF control CPU 110 of the APS request receiving node. For example, a flowchart of the IF control CPU 110 of the MPLS communication device 2 in FIG. 11 . the

When the IF control CPU 110 receives the APS request, it inserts an APS reply frame into the LSP opposite to the LSP that has received the APS request frame (S201). For example, in FIG. 9 , when an APS request frame is received from LSP1000 , an APS reply frame is inserted into LSP5000 . the

The IF control CPU 110 changes the operating system information in the operating system table 160 corresponding to the LSP that has received the APS request (S203). The actions and changes when receiving an APS request are the same as when receiving an APS reply. 6 and 10 are examples of tables of the MPLS communication device 1, but the MPLS communication device 2 may have the same table structure. For example, the operation system table is retrieved from the tag search ID that received the APS request, and the "operation system" of the corresponding item is changed to the operation system that received the APS. The same applies to the case where the MPLS communication device 1 receives an APS request from the MPLS communication device 2 . the

Then, the IF control CPU 110 notifies the overall control CPU 40 of operating system switching (S205). For example, system information after switching (for example, 1 system) is included. the

(LAG and MPLS OAM)

FIG. 14 is a schematic diagram showing problems of a communication device having LAG and MPLS OAM functions. the

LAG is a technology that bundles multiple physical ports as one logical port. Therefore, even when VLAN flows belonging to the same MPLS connection are input from different physical ports, they need to be transmitted through the same MPLS label path and the same path. However, a conventional MPLS communication device may not be able to transmit a VLAN frame through the same uplink connection because the label processing table is stored independently in the line IF. In addition, regarding the downlink frame, the switch 30 switches paths according to the LSP ID, so the frame can only be transmitted to a certain line IF. In addition, the uplink mentioned here refers to the direction from the Ethernet section to the MPLS section, and the downlink refers to the direction from the MPLS section to the Ethernet section. the

That is, conventional MPLS communication devices have, for example, the following problems. the

First, sometimes upstream frames cannot be transmitted through the same LSP. Also, sometimes only downlink frames can be transmitted. Since an OAM frame can only be transferred to one physical port, there is a possibility that the OAM end unit 108 of another physical port may be erroneously detected as a failure due to non-arrival of the OAM. the

When it is intended to transmit frames from multiple physical ports through the same LSP, the CV frames from each line IF are also sent through the same LSP, so in the opposite MPLS communication device, two or more CV frames of LSP, etc., that is, reception of more than a predetermined number of CV frames may result in erroneous recognition. In addition, since the line IF is biased at the transmission point of the downlink user frame, there is a possibility that the increase in the frequency band which is a benefit of implementing LAG cannot be realized. the

(link set and MPLS-connected system) 

Fig. 15 is a system configuration diagram of this embodiment. FIG. 16 is a structural example of the transfer table 310 and the LAG information database. the

The MPLS communication device 1 includes, for example, line IF#1, 2 (11, 12), uplink IF#1, 2 (21, 22), a switch 30, an overall control CPU 40, and a LAG information database 50. Overall, the CPU 40 is connected to each part via a bus or the like, for example. Also, a memory may be provided as appropriate. The switch 30 has a transfer table 310 . The transfer table 310 is, for example, as shown in FIG. 3( b ), and stores output port information corresponding to the ID. the

For the NW device (the first communication device), a plurality of physical ports are bundled and used as one logical port, and when the output destination of the received frame is the logical port, that is, the link set port, the frame is transmitted to any physical port among the link set ports . the

The MPLS communication device 1 is connected to the MPLS communication device 2 (second communication device) via a redundant MPLS network (communication network) via a system 0 LSP (first path) and a system 1 LSP (second path). The MPLS communication device 1 packs the frame input from the counterpart network device 3 into labels and transmits it to the MPLS communication device 2 , removes the label from the frame input from the MPLS communication device 2 , unpacks it, and transmits it to the counterpart network device 3 . the

Uplink IF#1 (21) is an interface for connecting to the 0 system LSP. Uplink IF#2 (22) is an interface for connecting to 1-system LSP. The line IF#1 ( 11 ) is an interface for connecting to the first physical port constituting the link set port facing the NW device 3 . The line IF#2 (12) is an interface for connecting to the second physical port constituting the link set port facing the NW device 3 . the

The switch 30 has labels corresponding to the system 0 LSP and the system 1 LSP, and stores the identifier of the interface unit as the transfer table 310 of the output location information. The switch 30 refers to the transfer table 310 based on the tag of the tagged frame, and transfers the frame according to the corresponding output destination information. the

Line IF#1 (11) has an OAMACT/SBY switching register (first storage unit) indicating the operating system or standby system for failure detection, and the first storage unit is set as the operating system. The line IF#2 (12) has an OAMACT/SBY switching register (second storage unit) indicating the operating system or the standby system for failure detection, and the second storage unit is set as the standby system. the

The line IF#1 (11) receives the user frame sent from the first physical port of the corresponding NW device 3, packs the user frame according to the label of the 0-system LSP, and transmits the user frame to the MPLS via the switch 30 through the 0-system LSP Communication device 2. The line IF#2 (12) receives the user frame transmitted from the second physical port of the corresponding NW device 3, packs the user frame according to the label of the 0-system LSP, and transmits the user frame to the MPLS via the switch 30 through the 0-system LSP Communication device 2. the

The line IF#1 (11) transmits a conduction confirmation frame to the MPLS communication device 2 based on the first storage unit set as the operating system. On the other hand, the line IF#2 (12) does not transmit the continuity confirmation frame to the MPLS communication device 2 based on the second storage unit set as the standby system. the

The transmission table 310 stores at least the identifier of the line IF#1 (11) set as the operating system, as the link received by the line IF#1 (11) and the line IF#2 (12) through the system 0 and the system 1 LSP. The output location information corresponding to the label in the downlink direction. The switch 30 transfers the connectivity confirmation frame received from the MPLS communication device 2 through the system 0 LSP and the system 1 LSP to the line IF#1 according to the transfer table 30 (11). the

The line IF#1 (11) receives the conduction confirmation frame transmitted by the MPLS communication device 2 at a predetermined interval, and detects that the first storage unit does not receive the conduction confirmation frame based on the first storage unit set as the operation system. Failure of 1 or 1 system LSP. On the other hand, the line IF#2 (12) does not perform failure detection due to non-reception of the continuity confirmation frame by the second storage unit set as the standby system. the

The MPLS communication device 1 also has a LAG information database. Fig. 16(b) shows an example of the structure of the LAG information database. In which physical port the LAG information database is saved for LAG setting. In the LAG information database, for example, corresponding to the physical port number, the LAG setting information indicating whether there is a LAG setting, the LAG port number (link set identification information) to which it belongs when there is a LAG setting, and OAM ACT/SBY setting information , and indicate whether there is a link failure in Ethernet (registered trademark, hereinafter the same). In addition, appropriate identification information may be used in addition to the port number. In this example, a physical port of LAG is set, and its LAG setting information is set to "1". For example, when the OAM ACT/SBY setting information is "1", it is the ACT system, and when it is "0", it is the SBY system. For example, when the failure information is "1", it indicates that there is a failure, and when it is "0", it indicates that there is no failure. the

Using this database information, the physical port serving as the ACT is set as the physical port of the output destination of the transfer destination table. For example, the downstream output port of the transfer table 310 corresponds to the physical port set as ACT in the LAG information database. Here, the ACT/SBY setting information corresponding to the physical port 1 is "1", that is, the ACT system, so the output port information corresponding to the downstream label (500, 5000) of the transfer table 310 stores the physical port 1 . the

FIG. 17 is a structural diagram of the line IF10. the

The line IF10 has a frame receiving circuit 101, a label ID retrieval unit 102, a manager 112, a label giving unit 103, a switching transmitting circuit 104, a switching receiving circuit 105, an MPLS label processing unit 106, a frame transmitting circuit 107, an OAM terminal unit 108, an OAM Insert part 109, IF control CPU 110, CPU interface 111, and OAM ACT/SBY switching register 200. the

In the OAM ACT/SBY switching register 200, the own line IF is set to the ACT system or the SBY system. For example, it can be set for each physical port. Also, the OAM ACT/SBY switching register 200 may be provided in each line IF section. In addition, the line IF and the information indicating ACT/SBY may be stored in association with each other outside the line IF. the

In order to transmit uplink frames input from multiple physical ports corresponding to LAG ports through the same MPLS LSP, the ingress label search ID table 150, operating system table 160, MPLS label table 170, egress label search ID table 180, and MPLS label table 190 The setting value of the LAG is set in advance to the same value among the line IFs that perform LAG. In addition, these settings can be performed by the overall control CPU40, for example. With this setting, even if the line IFs are different, frames received from the LAG port can be transmitted through the same MPLS LSP. the

For the non-reception of the conduction confirmation frame caused by the bias of the downlink frame according to the nature of the switch 30, the line IF (for example, line IF#1 (11)) set as the downlink output port in the switch 30 is set to OAM ACT performs OAM insertion and terminal processing (continuity confirmation processing). On the other hand, a line IF (for example, line IF #2 (12)) that is not set as a downstream output port in the switch 30 is set to OAM SBY, and OAM insertion processing and termination processing are not performed. For this processing, the line IF also has the OAM ACT/SBY flag in the LAG information database. This flag can be set per line. the

In addition, it is also possible to have a plurality of line IFs set to the SBY system, and perform preferential link aggregation among the plurality of IFs. For example, there is also a line IF#3 (fifth interface unit) set to the SBY system. In this case, although not shown in the figure, it is possible to set the SBY priority of the interface and use the SBY with higher priority as the ACT when the physical port of the ACT fails. For example, the priority may be pre-stored in an appropriate database or memory such as the LAG information database corresponding to the physical port. the

The line IF set to OAM SBY does not perform OAM insertion processing and OAM termination processing. Therefore, even when an ON frame of OAM is not received, a fault is not erroneously detected. With this setting, LAG and MPLS OAM can be realized at the same time. the

(Fault generation in the Ethernet section, ACT/SBY switching) 

Fig. 18 is a schematic diagram of ACT/SBY switching operation when a failure occurs in the Ethernet section. For example, a description will be given of a case where a failure occurs in a port on which LAG setting is performed or in a link corresponding to the port. the

When the LAG setting is performed and a failure occurs on the physical port (physical port 1 in this example) that becomes the OAM ACT, for the setting of the ACT/SBY flag of the LAG information database, the failed port is set as Set it as SBY, and set the port without failure as ACT. And, switch the OAM ACT/SBY switching register 200 of each line IF, set the port where the fault occurred as SBY, and set the port where the fault did not occur as ACT. the

Then, the setting of the transfer table 310 of the switch 30 is rewritten to a physical port where no failure has occurred. As a result, the operation can be continued, and the influence of a failure in the Ethernet section will not affect the transmission connection in the MPLS section. the

Fig. 19 is an example of a table structure after switching when a failure occurs in the Ethernet section. Fig. 20 and Fig. 21 are the switching flowcharts when a failure occurs in the Ethernet section. Hereinafter, an example of switching processing when a failure occurs in the Ethernet section will be specifically described. In addition, the transfer table 310 and the LAG information database before the occurrence of a failure will be described based on, for example, the setting state shown in FIG. 16 . the

FIG. 21( a ) is a flowchart of processing by the IC control CPU 110 in which a fault is detected in the line IF. the

When a failure occurs in a link in the Ethernet section, the IF control CPU 110 of the line IF detects link loss from a physical port (S400). In this example, for example, the IF control CPU 110 of the line IF #1 (11) executes the following processing when detecting that a failure has occurred. the

The IF controls the CPU 110 to set the OAM ACT/SBY register of its own line IF to SBY (S401). Then, the IF control CPU 110 notifies the overall control CPU 40 of the line IF link loss (S403). The notification may include the physical port number (physical port 1 in this example) corresponding to the own line IF. the

FIG. 20 is a flow chart of the processing of the overall control CPU 40 at the time of line IF failure detection. the

In general, when the control CPU 40 receives a notification of link loss from the line IF (S300), it executes the following processing. First, the overall control CPU 40 refers to the LAG information database (S301). For example, an item corresponding to the physical port number of the line IF that received the link loss is retrieved. In this example the item for physical port 1. And, the failure information of the corresponding item is set to 1, for example. the

The overall control CPU 40 judges whether or not the link loss detection physical port is a LAG port (S303). For example, referring to the LAG port information of the item retrieved in step S301, if it is "1", it is judged to be a LAG port, and if it is "0", it is judged not to be a LAG port. When it is judged that it is not a LAG port (S303, No), the process ends. the

On the other hand, when it is determined that it is a LAG port (S303, Yes), the overall control CPU 40 determines whether the link loss detection physical port is an OAM ACT port (S305). For example, with reference to the ACT/SBY setting information of the item retrieved in step S301, if it is "1", it is judged to be an OAM ACT port, and if it is "0", it is judged not to be an OAM ACT port (that is, an OAM SBY port). When judging that it is not an OAM ACT port (S305, No), the processing ends. the

On the other hand, when it is judged to be an OAM ACT port (S305, Yes), the overall control CPU 40 performs a change notification for setting the OAM ACT/SBY switching register 200 of any line IF belonging to the same LAG port to ACT (S307 ). More specifically, the overall control CPU 40 retrieves an item having the same LAG port information as that of the item retrieved in step S301 from the LAG information database. In this example the entry for physical port 2 of LAG port 1. Then, the overall control CPU 40 notifies the IF control CPU 110 of the line IF corresponding to the physical port of the corresponding item to set the OAM ACT/SBY switching register 200 to ACT. In addition, the overall control CPU 40 sets the ACT/SBY setting information of the corresponding item of the LAG information database to "1", that is, to ACT. And the overall control CPU40 sets the ACT/SBY setting information of the item searched in step S301 to "0", that is, to SBY. the

Then, the overall control CPU 40 changes the transfer table 310 (S309). For example, change the output port of the item of the old OAM ACT port to reset to the physical port information of OAM ACT. More specifically, the output port information corresponding to the downstream label (for example, 500, 5000) of the transfer table 310 shown in FIG. 19(a) is rewritten as the physical port information set as ACT in the LAG information database. Here, the physical port 2 is set as the ACT system ( FIG. 19( b )), so it is rewritten as the physical port 2 . the

FIG. 21( b ) is a flowchart of processing of the IF control CPU 110 that has received the change notification of the OAM ACT/SBY switching register 200 from the overall control CPU 40 . the

When the IF control CPU 110 of the line IF (line IF #2 (12) in this example) receives the register change notice from the overall control CPU 40, it sets the OAM ACT/SBY register of its own line IF to ACT (S451). the

Through the above processing, the line IF#2 (12) becomes the ACT system, and communication in the uplink and downlink directions can be continued. In addition, the OAM function can be continuously executed by performing OAM insertion processing and termination processing on the line IF#2 (12) set as the ACT system. In addition, in the opposite network device 3 , a link loss may be detected so that no frame is output to the link corresponding to the physical port 1 of the MPLS communication device 1 . the

(Fault generation in MPLS section, active/standby switching-2)

Fig. 22 is a schematic diagram of active/standby switching when a fault occurs in an MPLS section. the

Line IF#1 ( 11 ) and Line IF #2 ( 12 ) use the operating system table 160 to manage the paths of operating systems (system 0 here). For example, the line IF#1 (11) set to the ACT system detects a failure of the path of the operating system by failing to receive the OAM frame of the path corresponding to the operating system within a predetermined time. The line IF#1 (11) changes the operating system information in the operating system table 160 of its own line IF to the route of the backup system (here, system 1). For example, the operating system path is switched from system 0 to system 1 through the system switching operation in steps S101 to S109 described above. Then, for example, another line IF (for example, line IF #2 (12)) is notified via the overall control CPU 40 , and the other line IF that receives the notification changes the operating system information in the operating system table 160 of its own line IF to the route of the standby system. As a result, the operation can be continued and the influence of a failure in the MPLS section will not affect the Ethernet section. Frames input from physical ports 1 and 2 after system switching is also transmitted using 1 system LSP. the

Fig. 23 is a flow chart of active/standby switching when a failure occurs in the MPLS section. Fig. 23(a) is a flow chart of the processing of the overall control CPU 40 for generating an MPLS communication device using system switching. the

First, the processing of the above-mentioned steps S101 to S109 shown in FIG. 12 is executed. As a result, the operating system table 160 of the line IF (line IF#1(11) in this example) in which the failure of the MPLS section was detected is updated to 1 system, for example, as shown in FIG. 10( a ). In addition, the LAG information database before the occurrence of a failure will be described, for example, in the setting state shown in FIG. 16( b ). And, the operating system table 160 of the line IF#2 (12) is set as shown in FIG. 6(b). the

When the overall control CPU 40 receives the operation system switching notification from the IF control CPU 110 of the line IF that detected the failure (S500), it executes the following processing. In addition, the operating system switching notification may include the tag search ID, the operating system information after switching (system 1 in this example), and the physical port number (physical port 1 in this example) corresponding to the faulty line IF. ). the

The overall control CPU 40 refers to the LAG information database (S501). For example, the overall control CPU 40 searches for the item of the physical port number included in the received operating system switching notification. the

The overall control CPU 40 judges whether or not the LSP on which the operating system has been switched is a LAG port (S503). For example, the overall control CPU 40 refers to the LAG setting information of the searched item, and judges that it is a LAG port if it is "1", and judges that it is not a LAG port if it is "0". When it is judged that it is not a LAG port (S503: No), the process ends. the

On the other hand, when it is determined that it is a LAG port (S503: Yes), the overall control CPU 40 notifies the physical port that belongs to the same LAG port and is set as SBY to the label search ID and the operating system after the switching of the operating system. The IF controls CPU 110 (S505). More specifically, the overall control CPU 40 retrieves an item having the same LAG port information as that of the item retrieved in step S501 from the LAG information database. In the example of the LAG information database in FIG. 16( b ), it is an item of physical port 2 whose LAG port information is 1. Then, the overall control CPU 40 transmits an operation system switching notification including the tag search ID and the switched operation system information to the IF control CPU 110 of the line IF corresponding to the physical port of the corresponding item (for example, line IF#2 (12)). For the tag search ID and the operating system information after switching, the contents included in the operating system switching notification received in step S500 can be used. the

FIG. 23( b ) is a flowchart of processing of the IF control CPU 110 that receives the operation system switching notification from the overall control CPU 40 . the

For example, when the IF control CPU 110 of the line IF#2 (12) receives the operating system switching from the general control CPU 40, it searches the operating system table 160 according to the specified tag search ID, and rewrites the operating system to the specified system (S551). Thereby, the operation system table 160 of the link IF#2 (12) is updated to 1 system, for example as shown in FIG.10(a). the

After the operating system table 160 is updated from system 0 to system 1, when referring to the MPLS label table 170 in the line IF and assigning an MPLS label ID to an input frame, the item whose operating system is 1 is referred to. For example, in a table like FIG. 6(c), when the label search ID is 1, if the operating system information is 0, the MPLS label ID is 100, and if the operating system information is 1, the MPLS label ID is 1000. the

2. The second embodiment

Fig. 24 is a configuration diagram of a system according to the second embodiment. the

The ACT/SBY setting of OAM in this embodiment is the same as that in the first embodiment. In this embodiment, the SW 30 of the MPLS communication device 1 further includes a shuffling unit 330 . And, the transmission table 320 stores the output port information and the OAM ACT port information of the user frame corresponding to the label. Other structures are the same as those of the first embodiment. the

In the first embodiment, frames destined for the LAG port (downlink) are transmitted to any one of the line IFs, but in this embodiment, user frames are allocated to a plurality of line IFs. In addition, the OAM frame is transmitted to the line IF configured as the ACT system as in the first embodiment. the

FIG. 25 is a configuration diagram of a transfer table 320 according to the second embodiment. the

The transmission table 320 stores, for example, an identification indicating a link set as the first output location information for the user frame corresponding to the downlink label received by the uplink IF #1, 2 (21, 22) through the first and second paths. identifier, and the identifier of the line IF#1 (11) of the operating system as the second output location information for the conduction confirmation frame is set. the

The switch 30 identifies whether the frame received from the MPLS communication device 2 is a user frame or a continuity confirmation frame. For example, refer to the OAM tag of the frame. If an OAM tag is added or the OAM tag has a predetermined value (for example, 14), it is recognized as an OAM frame such as a continuity confirmation frame, and other frames can be recognized as a user frame. In the case of a user frame, the switch 30 selects one of the interface units belonging to the link set indicated by the first output location information of the transfer table 320 according to a preset rule. The switch 30 transmits the frame to the counterpart network device 3 through the selected interface unit. And, the switch 30 transfers the frame to the line IF#1 (11) according to the second output destination information of the transfer table 320 when it is the continuity confirmation frame. the

For example, regarding a user frame destined for a LAG port, in the SW30 of the MPLS communication device 1, not only the MPLS label but also the addressee address (DA) of the MAC and the ID for identifying the flow such as the VLAN are extracted from the original frame, and the Unit 330 performs shuffling calculations, and assigns them to physical ports according to the calculation results. Regarding hashing calculations, the same suitable methods as for LAG can be used. In addition, in addition to performing shuffling calculations, an appropriate method can also be used to select the output location of the downlink user frame from the physical ports belonging to the LAG. In addition, which physical port belongs to the LAG can be stored in advance. In addition, the above-mentioned LAG information database may be referred to. In this way, the downlink data can be prevented from being diverted to one port, and the OAM function can be further realized. the

When a LAG setting is performed and a physical port (for example, a port of line IF#1 (11)) that becomes an OAM ACT fails, as in the first embodiment above, regarding the setting of the ACT/SBY flag, the failure occurs Ports are set to SBY, and ports that do not generate faults are set to ACT. In addition, in the first embodiment, the output port information of the SW transfer table 320 is rewritten as a physical port number where no fault occurs, but in this embodiment, the OAM ACT port information of the transfer table 320 is rewritten as no fault occurs The physical port number of the port. For example, the OAM ACT port information in the transfer table 320 shown in FIG. 25 is rewritten as physical port 2. the

The present invention can be used, for example, in a system including a communication device having a link aggregation function and a communication device having an MPLS function. the

Claims (12)

1. A communication device that combines a plurality of physical ports to be used as one logical port, and when the output destination of a received frame is the logical port, that is, a link set port, the frame is transmitted to any one of the physical ports in the link set port. The first communication device is connected to the second communication device via the first bus and the second bus through a communication network having a redundant structure, and the frames input from the first communication device are packaged with tags and transmitted to the second communication device. The communication device removes the tag from the frame input by the second communication device and unpacks it, and transmits it to the first communication device. The communication device is characterized in that it has: a first interface part for connecting to a first bus; A second interface part for connecting to a second bus; a third interface unit for connecting to a first physical port of the first communication device constituting a link aggregation port; a fourth interface section for connecting to a second physical port of the first communication device constituting a link aggregation port; and The switching unit has a transfer table that stores the identifiers of the first to fourth interface units as output destination information corresponding to the tags of the first bus and the second bus, and based on the tag of the tagged frame, Referring to the transmission table, transmitting the frame according to the corresponding output target information, The third interface unit has a first storage unit configured as an active system or a standby system for failure detection, and the first storage unit is set as an active system, The fourth interface unit has a second storage unit in which an operating system or a backup system for failure detection is set, and the second storage unit is set as a backup system, The third interface unit receives the user frame sent from the first physical port of the first communication device, packs the user frame with the label of the first bus, and transmits the user frame through the first bus by the switching unit For the second communication device, The fourth interface unit receives the user frame sent from the second physical port of the first communication device, packs the user frame with the label of the first bus, and transmits the user frame through the first bus by the switching unit For the second communication device, The third interface unit transmits a conduction confirmation frame to the second communication device based on the first storage unit set as an operating system, The fourth interface unit does not transmit a conduction confirmation frame to the second communication device based on the second storage unit set as a backup system, The transmission table stores at least an identifier of the third interface unit set as an operating system as a tag in a downlink direction received by the first and second interface units through the first and second buses. Corresponding to the output destination information, the exchange unit transmits the conduction confirmation frame received from the second communication device through the first bus and the second bus to the third interface unit according to the transmission table, The third interface unit receives a conduction confirmation frame transmitted at predetermined intervals by the second communication device, and passes the conduction confirmation frame not received based on the first storage unit set as an operation system. , thereby detecting a failure of the 1st or 2nd bus, The fourth interface unit does not perform failure detection that a continuity confirmation frame is not received based on the second storage unit set as a backup system, The communication device further includes a control unit that controls the third interface unit, the fourth interface unit, and the switching unit, When the third interface unit detects that a link failure with the first communication device is detected, the first storage unit is set as a backup system, and a switching notification is sent to the control unit, When the control unit receives the switching notification, it sets the second storage unit of the fourth interface unit as an operating system. 2. The communication device according to claim 1, wherein: The control unit changes the output destination information corresponding to the tags in the downstream direction of the first bus and the second bus in the transfer table to the identifier set as the fourth interface unit of the operating system, thereby The conduction confirmation frame received from the second communication device through the first bus and the second bus is transmitted to the fourth interface unit according to the transmission table. 3. The communication device according to claim 1, further comprising: A link set information database, corresponding to the identifiers of the third and fourth interface parts, storing link set identification information for identifying the link set port to which the link connected to the interface part belongs; and a control unit that controls the third interface unit, the fourth interface unit, and the switching unit, When the third interface unit detects a link failure with the first communication device, the first storage unit is set as a backup system, and a switching notification is sent to the control unit, When the control unit receives the notification of switching from the third interface unit, it refers to the link set information database to obtain link set identification information corresponding to the identifier of the third interface unit, and obtains the link set identification information corresponding to the link set. an identifier of the fourth interface part of the link set identification information having the same identification information, The control unit sets the acquired second storage unit of the fourth interface unit as an operation system, The control unit changes the output destination information corresponding to the downlink labels of the first bus and the second bus in the transfer table to the acquired identifier of the fourth interface unit, thereby transferring the The second bus and the conduction confirmation frame received from the second communication device are transmitted to the fourth interface unit according to the transmission table. 4. The communication device according to claim 1, further comprising: a fifth interface unit for connecting to a third physical port constituting the link aggregation port of the first communication device; and a control unit that controls the third to fifth interface units and the switching unit, The fifth interface unit has a third storage unit set as an operating system for failure detection or a backup system, and the third storage unit is set as a backup system, The fourth interface unit and the fifth interface unit have preset priorities for changing to an operating system, When the third interface unit detects a link failure with the first communication device, the first storage unit is set as a backup system, and a switching notification is sent to the control unit, When the control unit receives the switching notification, it sets the second or third storage unit of the fourth or fifth interface unit as the operating system according to the set priority, The control unit changes the output destination information corresponding to the downlink labels of the first bus and the second bus in the transfer table to the identifier of the fourth or fifth interface unit according to the set priority, Accordingly, the conduction confirmation frame received from the second communication device via the first bus and the second bus is transmitted to the fourth or fifth interface unit according to the transmission table. 5. The communication device according to claim 1, further comprising a control unit for controlling the 3rd interface unit, the 4th interface unit and the switching unit, The third and fourth interface units respectively store operating system information indicating a first bus as an operating system of the communication network, When the third interface unit detects a failure of the first bus by failing to receive a continuity confirmation frame transmitted from the second communication device at a predetermined interval, or receives a system message from the second communication device When switching information, change the operating system information of the interface unit to the second bus, and send a switching notification to the control unit, When the control unit receives the switching notification, it changes the operating system information of the fourth interface unit to the second bus, The third and fourth interface units pack the user frame from the first communication device according to the label of the second bus according to the changed operating system information, and transmit the frame to the second communication device. 6. The communication device according to claim 5, further comprising a link collection information database, corresponding to the identifiers of the third and fourth interface parts, storing information for identifying the link to which the interface part belongs. The link set identification information of the link set port, When the control unit receives the notification of switching from the third interface unit, it refers to the link set information database to obtain link set identification information corresponding to the identifier of the third interface unit, and obtains the link set identification information corresponding to the link set. In accordance with the identifier of the fourth interface unit in the link set identification information having the same identification information, the operation system information of the fourth interface unit is changed to the second bus according to the acquired identifier. 7. The communication device according to claim 1, wherein the third and fourth interface units have: The first label retrieval table stores a preset label retrieval identifier corresponding to the virtual network identifier; The operating system table stores operating system information of a bus representing the operating system in correspondence with the tag search identifier, and rewrites the operating system information by detecting a failure of the bus; and The label table stores the labels of the first and second buses corresponding to the system information indicating the operating system or the standby system and the label search identifier, When the third and fourth interface units receive a user frame from the first communication device, extract a virtual network identifier from the user frame, According to the extracted virtual network identifier, refer to the first label retrieval table to obtain a corresponding label retrieval identifier, determining the operating system information with reference to the operating system table based on the acquired tag search identifier, According to the operating system information and the obtained tag search identifier, search the system information and the tag search identifier of the tag table, and obtain the corresponding first or second bus tag, The received user frame is packaged with the acquired tag, and transmitted to the second communication device. 8. The communication device according to claim 7, wherein the first tag search table, the operating system table, and the tag table are provided in the third interface unit and the fourth interface unit stored with the same content. 9. A communication device that combines a plurality of physical ports to be used as one logical port, and when the output destination of a received frame is the logical port, that is, a link set port, the frame is transmitted to any one of the physical ports in the link set port. The first communication device is connected to the second communication device via the first bus and the second bus through a communication network having a redundant structure, and the frames input from the first communication device are packaged with tags and transmitted to the second communication device. The communication device removes the tag from the frame input by the second communication device, unpacks it, and transmits it to the first communication device, The communication device is characterized in that it has: a first interface part for connecting to a first bus; A second interface part for connecting to a second bus; a third interface unit for connecting to a first physical port of the first communication device constituting a link aggregation port; a fourth interface section for connecting to a second physical port of the first communication device constituting a link aggregation port; and The switching unit has a transfer table that stores the identifiers of the first to fourth interface units as output destination information corresponding to the tags of the first bus and the second bus, and based on the tag of the tagged frame, Referring to the transmission table, transmitting the frame according to the corresponding output target information, The third interface unit has a first storage unit configured as an active system or a standby system for failure detection, and the first storage unit is set as an active system, The fourth interface unit has a second storage unit in which an operating system or a backup system for failure detection is set, and the second storage unit is set as a backup system, The third interface unit receives the user frame sent from the first physical port of the first communication device, packs the user frame with the label of the first bus, and transmits the user frame through the first bus by the switching unit For the second communication device, The fourth interface unit receives the user frame sent from the second physical port of the first communication device, packs the user frame with the label of the first bus, and transmits the user frame through the first bus by the switching unit For the second communication device, The third interface unit transmits a conduction confirmation frame to the second communication device based on the first storage unit set as an operating system, The fourth interface unit does not transmit a conduction confirmation frame to the second communication device based on the second storage unit set as a backup system, The transfer table stores at least an identifier indicating a link set as first output destination information for a user frame corresponding to a downlink label received by the first and second interface units via the first and second buses. , and as the second output destination information for the conduction confirmation frame is set as the identifier of the third interface unit of the operating system, the switching unit identifies whether the frame received from the second communication device is a user frame or a continuity confirmation frame, If it is a user frame, according to a preset rule, select one of the interface units belonging to the link set indicated by the first output destination information in the transfer table, and communicate with the first communication unit through the selected interface unit device transmits frames, If it is a conduction confirmation frame, the frame is transmitted to the third interface unit according to the second output destination information of the transmission table, The third interface unit receives a conduction confirmation frame transmitted at predetermined intervals by the second communication device, and passes the conduction confirmation frame not received based on the first storage unit set as an operation system. , thereby detecting a failure of the 1st or 2nd bus, The fourth interface unit does not perform failure detection that a continuity confirmation frame is not received based on the second storage unit set as a backup system. 10. The communication device according to claim 9, wherein, when the identified frame is a user frame, the exchange unit recognizes the flow based on the destination address of the frame input to the exchange unit and/or the identification flow Information, hash calculation is performed, and one of the interface parts belonging to the link set is selected according to the calculation result. 11. A communication system having: In the first communication device, a plurality of physical ports are combined to be used as one logical port, and when the output destination of the received frame is the logical port, that is, the link set port, the frame is transmitted to any one of the physical ports in the link set port; The second communication device is connected via the first bus and the second bus through a communication network with a redundant structure; and A third communication device, connected to the first communication device and the second communication device, packs the frame input from the first communication device with a tag and transmits it to the second communication device, and from the second communication device 2 removing the tag from the frame input by the communication device and unpacking it, and sending it to the first communication device, The communication system is characterized in that, The third communication device has: a first interface part for connecting to a first bus; A second interface part for connecting to a second bus; a third interface unit for connecting to a first physical port of the first communication device constituting a link aggregation port; a fourth interface section for connecting to a second physical port of the first communication device constituting a link aggregation port; and The switching unit has a transfer table that stores the identifiers of the first to fourth interface units as output destination information in tags corresponding to the first bus and the second bus, and refers to all The above transmission table, transmit the frame according to the corresponding output target information, The third interface unit has a first storage unit set as an active system or a backup system for failure detection, and the first storage unit is set as an active system, The fourth interface unit has a second storage unit set as an operating system for failure detection or a backup system, and the second storage unit is set as a backup system, The third interface unit receives the user frame sent from the first physical port of the first communication device, packs the user frame with the label of the first bus, and transmits the user frame through the first bus by the switching unit For the second communication device, The fourth interface unit receives the user frame sent from the second physical port of the first communication device, packs the user frame with the label of the first bus, and transmits the user frame through the first bus by the switching unit For the second communication device, The third interface unit transmits a conduction confirmation frame to the second communication device based on the first storage unit set as an operating system, The fourth interface unit does not transmit a conduction confirmation frame to the second communication device based on the second storage unit set as a backup system, The transmission table stores at least an identifier of the third interface unit set as an operating system as a tag in a downlink direction received by the first and second interface units through the first and second buses. Corresponding to the output destination information, the exchange unit transmits the conduction confirmation frame received from the second communication device through the first bus and the second bus to the third interface unit according to the transmission table, The third interface unit receives a conduction confirmation frame transmitted at predetermined intervals by the second communication device, and passes the conduction confirmation frame not received based on the first storage unit set as an operation system. , thereby detecting a failure of the 1st or 2nd bus, The fourth interface unit does not perform failure detection that a continuity confirmation frame is not received based on the second storage unit set as a backup system. 12. A communication system having: In the first communication device, a plurality of physical ports are combined to be used as one logical port, and when the output destination of the received frame is the logical port, that is, the link set port, the frame is transmitted to any one of the physical ports in the link set port; The second communication device is connected via the first bus and the second bus through a communication network with a redundant structure; and A third communication device, connected to the first communication device and the second communication device, packs the frame input from the first communication device with a tag and transmits it to the second communication device, and from the second communication device 2 removing the tag from the frame input by the communication device and unpacking it, and sending it to the first communication device, The communication system is characterized in that, The third communication device has: a first interface part for connecting to a first bus; A second interface part for connecting to a second bus; a third interface unit for connecting to a first physical port of the first communication device constituting a link aggregation port; a fourth interface section for connecting to a second physical port of the first communication device constituting a link aggregation port; and The switching unit has a transfer table that stores the identifiers of the first to fourth interface units as output destination information in tags corresponding to the first bus and the second bus, and refers to all The above transmission table, transmit the frame according to the corresponding output target information, The third interface unit has a first storage unit configured as an active system or a standby system for failure detection, and the first storage unit is set as an active system, The fourth interface unit has a second storage unit in which an operating system or a backup system for failure detection is set, and the second storage unit is set as a backup system, The third interface unit receives the user frame sent from the first physical port of the first communication device, packs the user frame with the label of the first bus, and transmits the user frame through the first bus by the switching unit For the second communication device, The fourth interface unit receives the user frame sent from the second physical port of the first communication device, packs the user frame with the label of the first bus, and transmits the user frame through the first bus by the switching unit For the second communication device, The third interface unit transmits a conduction confirmation frame to the second communication device based on the first storage unit set as an operating system, The fourth interface unit does not transmit a conduction confirmation frame to the second communication device based on the second storage unit set as a backup system, The transfer table stores at least an identifier indicating a link set as first output destination information for a user frame corresponding to a downlink label received by the first and second interface units via the first and second buses. , and as the second output destination information for the conduction confirmation frame is set as the identifier of the third interface unit of the operating system, the switching unit identifies whether the frame received from the second communication device is a user frame or a continuity confirmation frame, If it is a user frame, according to a preset rule, select one of the interface units belonging to the link set indicated by the first output destination information in the transmission table, and transmit to the first communication device through the selected interface unit frame, If it is a conduction confirmation frame, the frame is transmitted to the third interface unit according to the second output destination information of the transmission table, The third interface unit receives a conduction confirmation frame transmitted at predetermined intervals by the second communication device, and passes the conduction confirmation frame not received based on the first storage unit set as an operation system. , thereby detecting a failure of the 1st or 2nd bus, The fourth interface unit does not perform failure detection that a continuity confirmation frame is not received based on the second storage unit set as a backup system.

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